I am on the verge of buying a new hard disk but before I do that I wanted to exhaust all of the possible troubleshooting I can do before giving up on my 1.5 year old disk.

So my hard drive started acting weird probably a month ago. From time to time my pc would suddenly restart and display a message "boot mgr missing". I know that message means that the pc cant detect an os. I would be able to fix it by unplugging and plugging the sata cord from the hard drive.

I have ruled out the possibility that it was the os because I checked the bios and my hdd wasnt there. I ruled out the sata cord because I had a spare and it still happens after replacing it. I also ruled out the sockets from my mobo because I also tried plugging it on other sata sockets. It started happening more often.

I checked the hdd health in defraggler and it said that my hdd was healthy, performed tests with sea tools and there were still no errors. Soooo do you guys think my hdd is about to die or can I still save it?

  • Another possibility is a power issue - the hard disk is not getting enough power / quickly enough at boot time, and so isn't ready by the time the bios tries to find the boot sector. I don't suppose you have a spare PSU? It seems like the disk itself is healthy, so otherwise it might be the physical connection in the hd itself may have an issue. Dust?
    – Paul
    Dec 11, 2015 at 0:14
  • I wanna try the connection thing. Sadly i dont have a spare psu. I have another hdd installed that doesnt disappear so I think i can rule out the power veing a problem
    – Kobowo
    Dec 11, 2015 at 2:01
  • 1
    Is it a western digital hard drive? If so, that is a feature that all WD drives have, random failure. ;)
    – Richie086
    Dec 11, 2015 at 2:56
  • @Richie086 I can say that about all the main manus :) Hard disks fail, and often in batches. Then you vow to never use them again, but then your next manu has a bad run. Eventually you end up back with WD and the cycle starts over.
    – Paul
    Dec 11, 2015 at 4:23
  • My experience with failing WD drives is from when I had a job fixing PCs. I easily had to RMA over 100 WD drives in a 3 year period, when RMAs from other manufactures rarely went above 10 total during that same timespan. Just an observation, your mileage may vary.
    – Richie086
    Dec 11, 2015 at 4:54

2 Answers 2


There can be 3 possible issues: HDD surface degradation (bad sectors starting to appear and are remapped from HDD itself from time to time), HDD power issue, OS issue.

  1. The correct way to test the HDD is to scan its surface using tools time HDDScan or HDTune and to check SMART attributes for the drive. So, actually you need to check SMART first. Here is the list of attributes description. What you need to make sure that "Reallocated Sector Count" value, "Relocation Event Count" and "Current pending sector count" raw data values = 0. That means that there are no detected bad sectors that have been relocated. After that you need to make sure that all the other value are above the thresholds. Additional information about the data values and how to read them is here.

After that you need to scan the surface in the read+verify mode. That means that every sector will be read and its read speed will be measured. You need to make sure that there is no sectors with >=250 ms speed rate (normal rate is up to 50 ms). Here is the guide.

  1. The next part is that you need to make sure that your PSU +12V power line is stable and current on it is enough for the hard drive. If you hear clicking sound and after that a sound like when the motor is turning off that means that HDD is parking its reading magnetic heads and powered off. This can happen due to the unstable PSU. The easiest way to diagnose it - to try another PSU or at least disconnect all other devices consuming power from +12V line.

  2. The last thing is OS itself. Quite often bootmgr is damaged when the compression of the C drive is turned on. Make sure that it is off (in the C drive properties > untick checkbox "Compress this drive to save disk space").



  1. Failing SATA Bus
  2. Failing drive controller
  3. Unreliable power / lose connection

1 is ruled out due to the other drive being ok. 3 is unlikely has you've changed it around. That leaves the drives on controller being the likely culprit. HDD health tests cant detect issues with the controller. RMA it.

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